Objective: To perform a study comparing the efficacy of extra-fine particle HFA-QVAR 200 µg b.i.d. to an equipotent dose of course particle HFA-beclomethasone (HFA-Clenil) 400 µg b.i.d. and with coarse particle HFA-fluticasone (GSK) 250 µg in ex-smokers and smokers with asthma.